Art of color-printing.



PATENTED APR. 11, 1905.

M. A. McKEB.

ART OF COLOR PRINTING.

APPLICATION FILED MAY 10, 1904.

2 SHEETS-SHEET 1.

PATENTED APR. 11, 1906.

M. A. MQKEE.

ART OF COLOR PRINTING.

APPLIOATION FILED MAY 10, 1904.

2 SHEETS-SHEET 2.

UNTTED STATES Patented April 11, 1905 PATENT OFFICE.

MILTON A. McKEE, OF NElY YORK, N. ASSIGNOR TO O. B. OOTTRELL & SONSCOMPANY, OF NElV YORK, N. Y., A CORPORATION OF NElV J ERSEY.

ART OF COLOR-PRINTING.

SPECIFICATION forming part of Letters Patent No. 787,209, dated April11, 1905.

Application filed May 10,1904. Serial No. 207,202.

To rL/X 1/41/0111, if mil concern;

Be it known that I, MIL'roN A. McKee, a citizen of the United States,and a resident of the borough of Manhattan, in the city and State of NewYork, have invented a new and useful l mprovement in the Art ofColor-Printing, of which the following is a specification.

This invention consists in the continuous process hereinafter describedand claimed of printing in colors in which there are employed aplurality of printing-plates, one for each color, having what is knownas makeready in their own faces that is to say, eachof said plateshaving in its own printingsurface and the several plates having in theirrespective printing-surfaces gradations, according to the heavier andlighter printing pressures required for the different parts of eachplate and for the different plates. The several plates are employed incombination with a means for producing a printing impression theimpression-cylinder of a printing-press, for exainple-which is common toall of them, the supports for said plates andsaid means for producingthe impression being so mounted, proportioned, speeded, timedv geared,and registered together that the impressions from the several plateswill be taken or given upon one and the same portion of the sheet or webto be printed For carrying out this invention the makeready in the facesof the plates may be produced in any suitable manner--for example, bythe process which is the subject of my application for United Statespatent, Serial No. 80,789, filed December 21, 1901, the principalfeature of which consists in mechanically producing gradations ordifferences of printinglevel in different parts of the face of aprinting-plate by pressure in a matrix. The invention may be performedin any suitable printing-press for example,

a press having one impression-cylinder and as many form-cylinders asthere are colors to be printed.

ln the simple example which I have selected for the illustration andexplanation of my invention three printing-plates only are used for asmany colors-viz., yellow, red,

and bluethese being sufficient to produce colored pictures of greatattractiveness, though for greater effectiveness a fourth plate forblack may be used and other additional plates for other colors may beused with still greater advantage.

In the accompanying drawings, Figures I, II, and [ll represent the facesof the three made-ready printing-plates; Figs. 1, ll, and ll l,sectionsof said plates 1., ll, ll I, respectively, in the lines (t thereof,showing the differences of the printing-levels; and Fig. TV, a diagramof one end of the impres sion-cylinder and of each of the three platecylinders of a rotary color-printing press in which my plates forprinting the three colors are employed.

In the face Views of the plate the printingsurfaces are designated byshade-lines running in different directions, these lines on the yellowplate y, Fig. I, runningdiagonally, those on the red plate 1', Fig. ll,'ertically, and those on the blue plate I), Fig. Ill, horizontally. Thegradations of the printingsurface are representml by gradations of theshade-lines, the thicker lines and portions of lines indicating thehigher parts of the surfaces which are to print with heavier pres suresand the thinner lines indicating the lower parts of the surface whichare to print with lighter pressures. By a comparison of this shading inthe face views with the sectional views of the plates, thecorrespoinling portions of the plates having similar reference-numeralsin the two sets of figures, it will be seen that the plates are somewhatthicker and thinner in different parts, according to the heavier andlighter impression which they are to produce. This dif'l'erence ofthickness is represented somewhat exaggerated in the sectional views forthe sake of greater perspicuity.

The yellow plate, Figs. I and I, is representcd as having the greatestsurface of the three for the heaviest impression. All the parts marked 1are at the highest and strongest level, the parts marked 2 at the leveljust below, and the parts marked 3 the lowest level. There are onlythree gradations 01' levels in this plate. The red plate, Figs. II andIP, is represented as having four gradations or printing-levels. Theparts marked 1 are at the highest and strongest printinglevel, the parts2 being at the next lower level, the parts marked 3 at a still lowerlevel, and the parts 4 at the lowest level. These last give the lightestimpressions. In the blue plate, Figs. III and III there are also fourgradations, marked 1, 2, 3, and 4, as in Figs. II and 11 It may be seenby a comparison of the Figs. I, II, III that the plates all have adifferent character, the most conspicuous difference being between theyellow and the blue plates, the part 4 in the last-mentioned forproducing the lightest impression corresponding in position with one ofthe parts 1 of the yellow plate which produces the heaviest impression.

In whatever description of printing-press the printing with these platesis to be performed the impression-cylinder and the platesupports must beso mounted, proportioned, speeded, timed, geared, and registeredtogether that the impressions will be taken or given upon the sameportion of the circumierence of the impression-cylinder.

The diagram Fig. IV, representing the impression-cylinder 5 and threeplate-cylinders 6 7 8 and parts of three sets of inking-rollers 9 forthe several plate-cylinders of a known form of color-printing press,will be sufficient to render intelligible to those skilled in the artsof printing machinery and printing how the printing from the platesdescribed may be performed, the plate-cylinders and impression-cylinderbeing so proportioned in circumference, the plate-cylinders being atsuch distance apart, and the plates being so set upon their respectivecylinders and the impression and plate cylinders being so gearedtogether and registered that the plates will all come exactly intoregister with each other and opposite exactly the same part of theimpression-cylinder. The act of printing may be performed either on asheet or upon a continuous web 10.

In the diagram Fig. IV, in which the direction of the revolution of theseveral cylinders is shown on them by arrows, the yellow plate on thecylinder 6 is represented as printing. After the said plate has passedthe part of the impression-cylinder 8 by which the im pression is giventhe revolutions of the said cylinder and of the cylinder 7 will bringthe red plate 1" around in time to print the red impression upon theyellow one. After this im pression has been'made the continuedrevolution of the impression-cylinder and of cylinder 8 will bring roundthe blue plate I) in time to print the blue impression upon the red one.The three impressions now having been given directly one upon another inexact register will have produced a perfect picture in color.

I have described particularly for illustration of my invention theprinting with three colors, as it is probable that three will be thenumber very commonly used; but it will be obvious that for somework onlytwo might be produced and for other work many more might be used.

In carrying out this invention as described no make-ready, such as iscommon, is required upon the impression-cylinder or tympan of theprinting-press, and, infact, no such make-ready would be practicable,because the separate color-plates having different color-printing valuesall strike upon one place on the impression-cylinder and requiredifferent strengths of impression at corresponding parts of theirseveral faces. Suppose, for example, that any color-plate has at onepoint or part a dark printing tone, requiring considerable ink andnecessarily a strong printing impression, the next succeedingcolor-plate might be of a character the very reverse, having a lightprinting tone, requiring a light printing impression at the point orpart corresponding with the dark point or part of its predecessor. Itwould be impossible under these conditions to add to theimpression-cylinder any pieces of paper such as constitute an ordinaryoverlay for the benefit of the dark point or part in the one platewithout increasing too much the impression at the corresponding point orpart of the said succeeding plate, which might require a very lightprinting impression. It is therefore impossible by the hitherto knownmeans and processes for multicolor-printing to produce by a continuousoperation consisting in one passage of a sheet through a press a picturein which the differing color values of corresponding parts of two ormore color-plates would be efiectively brought out. Therefore it hasbeen customary for the finest multicolor-printing to print in only onecolor at a time at each passage of the sheet through the press,requiring as many separate and independent printings as there are colorsem ployed.

What I claim as my invention is 1. The improvement in the art ofcolorprinting which consists in printing in different colors by acontinuous operation upon the same portion of a sheet or web from platesone for each color, in the faces of which there are gradations ofprinting-level according to the heavier and lighter printing impressionsrequired from different parts thereof and in one of which plates thesaid gradations difier from those of another or others.

2. The improvement in the art of colorprinting which consists in firstpreparing a plurality of printing-plates one for each of IIS the colorsto be printed, each of said plates having in its face gradationsaccording to the heavier and lighter printing impressions to be producedby different parts thereof and the said gradations differing in theseveral plates according to the difference of pressure required on orfrom their corresponding parts, and then printing from said platessuccessively with a different color for each on the same portion of asheet or Web to produce a colored picture.

3. The improvement in the art of colorprinting which consists in firstpreparing a plurality of printing-plates one for each of the colors tobe printed, each of said plates having in its face gradations accordingto the heavier and lighter printing impressions to be produced bydifferent parts thereof and the said gradations differing in the severalplates, next mounting said plates on differ ent supports and then by acontinuous operation printing from said plates successively with theirrespective colors on the same portion of a sheet or Web.

4. The improvement in the art of colorprinting which consists inprinting successively upon the same portion of a sheet or Web from aseries of plates each having make-ready formed in its face and themake-ready being different in the different plates. Y

In testimony that I claim the foregoing as my invention I have signed myname, in presence of two Witnesses, this 6th day of May, 1904.

MILTON A. MOKEE.

Witnesses:

FREDK. HAYNEs, C. S. SUNDGREN.

